Making hollow shoe forms



Oct. 4, 1932. 5 EDDlNs ET AL 1,880,920

MAKING HOLLOW SHOE FORMS Filed June 1. 1928 2 Sheets-Sheet l 1932- s. A. EDDINS ET AL 1,880,920

MAKING HOLLOW SHOE FORMS Filed June l. 1928 2 Sheets-Sheet 2 Patented Oct. 4, 1932 UNITED STATES PATENT errata SEXTUS A. EDDINS AND GERALD M. HANNIGAN, OF QUINCY, MASSACI-I USETTS, AS- SIGNORS TO CORDO-HYDE COMPANY, OF BROCKTON, MASSACHUSETTS, A FIRM COM- POSED OF FRANCIS HANNIGAN AND SEXTUS A. EDDINS MAKING HOLLOW SHOE roams Application filed June 1, 1928. Serial No. 282,075. 7

i! from sheet celluloid.

In the production of hollow articles from Cellulose nitrates, such as sheet celluloid, various methods areemployed. One method 4 which is Well known involves the use of hot to allow it to be bent, coacting metal molds being employed to shape the celluloid wh1le in its tempered condition. It will be obvious, however, that such metal molds are relatively l l expensive and that unless a great number of identical articles are to bemade, the process is not economical. In the production of hollow celluloid shoe forms a great number of molds would be needed because of the variety T of sizes and shapes desired. Consequently, it is the common practice to employ wooden last-shaped models about which sheet celluloid is molded since such models may be produced upon last lathes in quantity at reasonable expense. Quite clearly, however, wooden models are not well adapted for use where either hot water or steam is the tempering agent employed, because of the deleterious effect of moisture upon the wooden models and the very real probability that the size and shape of the models would be changed. Consequently, as is well understood in the artof molding celluloid the sheet celluloid em} ployed for producing shoe forms may be tempered by means of a chemical softener, which is commonly a solvent, the form beingproduced by wrapping the tempered material around a model and allowing it toshrink into contact with the model. As heretofore practiced, this procedure has been attended by various disadvantages among the chief of which is the necessity for holding the blank in tight contact with the model during the whole of the shrinking or settingprocess.

Accordingly, in order to obviate the above stated and other disadvantages, the present invention, in its method aspect, is character ized by the application of localized resilient pressure to sheet material, such as celluloid tempered by the use of a suitable solvent,

water or steam for tempering the celluloid after the tempered sheet material has been wrapped about a suitably shaped 'model, thereby shaping the sheet material to the model, the pressure being preferably continued only so long as is necessary tocause' the shaped sheet material to acquire the shape of the model and a'preliminary set or rigidity."

As herein exemplified, a'hollow shoeform, illustrated as the toe piece of a shoe tree of the type-set forth in United States Letters Patent No. 1,776,831, granted September 30, 1930, upon our application, is produced by wrapping a blank'of chemically tempered sheet celluloid around a last-shaped wooden model and, by the application of localized resilient clamping pressure, forcing the blank closely against the model, marginal portions of the blank being drawn .tightly over the edge formedby the junction of the side and bottom faces of the model and pressed against the bottom face of the model. .Advanta geously, also, additional press'ure'is then appliedto marginal portions of the blank overlying the bottom face of the model to insure that they will lie flat'against the bottom face of the model; Preferably too, the blank is similarly drawnby resilient pressure into the recessed portion just forward of the instep portion of the model, the rear edge portion of theblank adjacent tothe'instep being also forced tightly against the model. vThus the blank, as it shrinks, is brought into substantially exactconformity with the model with out the need of constant attention on the part of an operator during'the'shrinking and setting of the blank, and without the exercise of any particular care or skill on the part of the operator. The application ofvpressure in the manner above stated is continued only so long as is necessary to causethe shaped sheet material to assume the shape of the model and take on a preliminary set after which the pressure is relieved and the'blank allowed to shrink into close contact with the model and to assume apermanent set.

' Conveniently, when the tempered blank is initially applied to the model, one edge of vthe blank is firstsecured t0 the model, the blankis wrapped around the model and the other edge of the blank is then secured to'the model. This may readily be accomplished by utilizing a model provided with retaining studs adapted to enter holes in the blank.

In another aspect, the invention provides an improvedapparatus for molding hollow forms, such as shoe forms, including a model provided with retaining devices for ablank from which a form is to be molded and with which there may be associated a clamping plate and Oneor more resilient bands, and a conveniently adjustable supporting spindleshoe form into close engagement therewith and a headed-screw being provided detachably. to secure the plate in clampingrelation tothe model: The illustrated spindle for holding themodel while the various steps ofthe method are carried out is rotatably mounted for turning movement about'its longitudinal axis and for turning movement about a horizontal axis to bring it, into various positions relatively to the operator to facilitate the desired treatment'of the blank,

. means beingprovided for locking thespindle in each of the positions which ita ssumesa I, These and other features of the invention will now, be set forth in detail with reference to the accompanying drawings in which, 7 vFig. l is a perspective view showing the model. mounted on its supporting spindle with atempered blank partially wrapped around the model; Figs. 2, 3, 4: and 5 areperspectiveviews of the model in inverted position showingsuce cessive steps in the method offorming' a previously tempered blankwhich is to be shaped like the model; r

.' Fig. 6 is alongitudinal vertical section through .themodeland partiallylcompleted form, showing the parts atthe stagevinthe manufacture of theformwhich is illustrated inFigAl; p f

Fig. 7 isa transverse section through the model and partially completed form along the line: of the studs on the bottom face of. themodel,and V i p I N (Fig. 8 isa perspectiveview of a portion of acompletedform and associated parts of a shoe tree. of the type above referred to. p For convenience, the method of molding hollow articles herein set-forth will be *described in. its application to themanufacture of the toe piece of ashoe tree of the type referred to, such as is illustrated in Fig. 8,

1,880,920 :J'. mi;

although it should be understood that in various aspects, the invention is equally ap plicable to the molding of other hollow articles of, different shapes and for different purposes. So, too, the invention will be particularly described as applied to the utilization of sheet celluloid, although in various aspects the invention is not limited to the use ofsuch'material. I Preparatory to the molding forms, suitably shaped blanks are cut from sheets of celluloid in any desired manner, either manuallyor by the use of dies, as found most economical, depending upon the quantity to be produced. The particular shoe tree which is illustrated in Fig. 8 comprises a toe piece and a spring heel piece and is ,designed for use in womens' shoes of which, in each style, there are commonly thirteen. length sizes and half sizesand a number'of widths in each length size. It has been found, however, that by providing toe piece blanks of three sizes and,utilizing,flin connection with these blanks, heel pieces ,or springs of two different lengths, a set of shoe trees of five difierent'sizes may be produced which set by reason ofthe resilience of the toe pieces and the resilience of the-heel pieces will be well adaptedfor a complete line of shoes. If found desirable before cutting out the blanks, the sheet celluloid is tempered or softenedslightlyby treatment with a suitable chemical tempering agent, commonly a solvent such, for example, as'diluted acetone or alcohol. Such treatment, however, is not absolutely necessary. and is only utilized in order to facilitate the cutting operation. The blanks may be fastened so that they are symmetrical about a center line from front to back withoutregard to whether they are to be used for right or left shoes, as itis found that the material. when tempered has suflicient stretch so thatit will accom- I modate itself to a last-shaped model, such as that villustrated in the drawings. Atv the same time that the blank is cut out it may be provided withapertures 12 in tab portionsll which are to be folded over the flat bottom of the model 10. p 7 v These blanks are then given additional tempering treatment by placing them in a pickling vat containing-any of the well known chemical softeners or solvents for celluloid such asdiluted acetone. The blanks are left in this pickling vat until they become soft and stretchy. The material in this condition is pliable and may be distorted at will, it having sufficient strength so thatit will undergo a substantial amount of stretching without tearing. The strength of the solution used may be varied/considerably and the time required varies substantially inversely with the strength of the pickle. Preferably, the material is so treated that it is brought to a dead! point where there is no more normal of hollow shoe expansion of the material under the action of the pickle.

Blanks which'have been thus treated are removed from the pickling vat and one of the perforations 12 in a tab 14 is hooked over a stud 16 projecting from the flattened bottom of the model 10. The blank is then Wrapped over the top of the model and the other tab 14 hooked over the other stud 18 so that the blank is wrapped closely around the model and is held in interlocked relation with the studs thereon. As a guide in positioning the blank around the top of the model a gage member such as a double pointed tack 19 driven into the model may be provided in the form to assist the operator in placing the edge of the blank which will ultimately form 8 the upper edge of'the shoe tree close to or in contact with the head of the tack.

V For positioning the model having the blank thereon for the subsequent steps of the process, the model 10 may be most conveniently handled if it is supportedin adjustable position upon a spindle 20 which has a projecting portion adapted to be inserted into a socket 22 in the model. This socket has at its outer end an annular plate 24 and both the plate and the model are provided with a key-way 26 to receive a key 28 on the spindle so thatthe model is non-rotatable with .respect to the spindle. The spindle itself is, however, mounted for rotation about its own axis in an arm 30 which is swiveled on a horizontal pivot 32 carried in a block 34 which is mounted on a base plate 36. This plate is adapted to be bolted to a suitable bench. The spindle carrying arm 30 may be swung to either oneof two inclined positions, tipping to the rear away from the operator, as shown in Fig. 1, or forwardly toward the operator and may be locked in either of those positions by a bolt 38. pressed upwardly by a spring 44 and received in sockets 40 in the arm 30. A finger piece 42 is provided for, unlocking the bolt against the tension of the spring when it is desired to shift the arm 30 from front to back. The spindle 20 is rotatably held in the arm 30 by means of retaining screws 46 entering a groove in said spindle. V] hen desired the spindle may be non-rotatably held in the arm 30 in either of two positions by means of a finger latch 48 spring pressed into'engagement with a slot at the lower end of the spindle 20. The'apparatus thus described provides for the presentation .of the model 10 in any one of four positions with a minimum of eflort upon the part of the operator and enables him to carry out the various steps of the method to be more fully described, with great facility.

After the blank has been hooked over the studs 16 and 18 in the model,the fingerlatch 42 is depressed and the spindle 20turned to its forwardly inclined position so that the blank overlies the upper surface of the lastlike model. At this time, the blank preferably is pressed into engagement with the recessed portion 50 (Fig. 6) of the model by pulling it down into contact'with the model with a strip of cloth (not shown) or in any other convenient fashion.

Thespindle is then moved to the position shown in Fig. 1 for the formation of the toe portion of the form 52 by resiliently banding the blank and model. For this purpose a rubber band 54 (Fig. 2) is applied over the extreme outer end of the toe portion of the form and the model in the position indicated in Fig. 2 and is engaged with a hook 56 projecting from the bottom face of the model. The rubber band 54 is separablefrom, and readily'transportable with, the model and acts as a resilient pressure member to apply localized pressure to draw the celluloid up close to the toe portion of the model and tightly over the sharp corner 58 at the edge of the fiat bottom face 60 of said model. It is desired to cause the celluloid to form a narrow flange 62 around the toe portion of the form 52 which will lie flat against the bottom face 60 of the model so that inthe fin- V ished article it will in conjunction with the tabs 14 form an open bottom for the shoe tree; V/hen the rubber band is applied it only slightly overlaps the bottom of the model and the sheet celluloid may or may not turn over the corner 58 .of the model at all. It

is found, however, that both the form and tially uniform flange 62 with the exercise 8 of no more than ordinary care. The tension of the band 54 will cause the celluloid to engage the form closely over substantially the whole of the toe portion and will maintain a uniform localized pressure against the parts of the form against which the band acts, the band acting continually to draw the celluloid against the model while the pickle or solvent is evaporating from the celluloid and the latter is beginning to set. As is well understood in the art, the setting of celluloid into rigid shape is accompanied by a shrink ing action which still further tends to draw it into tight contact with the surface of the model 10 so that it will assumethe exact shape of the model.

There may be a tendency, for the tabs 14 when the celluloid stiffens, to stand away from the bottom 60 adjacent to the ball portion of the model and to fail to assume; that substantially flat condition which is: illustrated in Figs. 6 and 7 and is desired in the finished article. Accordingly, in order still further to improve theiinished article, an apertured rigid clamping plate 64, which maybe ofthin brass, is provided. The plate 64 has perforations 66'to receive the studs 16 and 18 so that the plate mayengage and press against the rubber band 54. The plate 64 is also provided with two larger, more or less keyhole shaped openings 68 and 7 0 and when the plate is applied to the bottom of the model as shown in Fig. 3, it is partly positioned beneath the head of aclamping screw 74, projecting from the bottom face oI the model and is snapped past a spring pressed temporary retaining stud 72 carried by the model on its bottom face and urged to projecting position by a spring 82 (Fig. 6) thereby to allow full engagement beneath the head of the clamping screw 7 4 which extends through the opening 68, the stud 72 extending through the opening 70. After the clamping plate 64 has been applied, the screw 74 may be tightened in order to draw theplate into firm engagement with the rubber band 54 to press the tabs 14 and a portion of the flange 62 against the bottom face of the model.

After the clamping plate 64 has been applied, the rubber band 54inay be disengaged from the hook-56, as shown in Fig. 4, and'another rubber band 76 applied to the form and the model in a plane substantially at right angles to the plane of the band 54 to draw the instep portion 78 of th'e form tightly against the model. This instep portion is adjacent to the rear margin of the form so that there may be a slight tendency for the rear edge'oi the blank to curl away from the model. Any such tendency is overcome by the action of the band 76. r

It has been found that the rubber band 76 only needs to be left in position for a relatively short time, say, half an hour, after which it may be removed from the model for re-use: Theother rubber-band 54 may be removed at about the same time or if de sired, it may be allowed to remain in engagement with the toe of the form for a longer period. "At any rate, the band 54 is"usually turned back to bring it into the position illustrated in Fig. 5 before the operator leaves for the night. The clamping plates 64 are retained in position, however, usually over night, after which they may be removed together with the rubber band 54 by depressing the stud 72or by loosening the screw '74.

The form is then removed from the model by disengaging the tabs-14 from the studs 16 and 18 and slipping the model 05 the form. This operation is facilitated by making one of the studs 18 depressible against the tension of thespring 80 as shown in Fig. 7; By the time the form has, been removed from the model, the shrinking of the form has entirely ceased and the toe piece of the shoe tree will retain its shape indefinitely. If, in the process above described, the surface of the celluloid has been slightly dulled, it-may be brought back to its original brilliance by treatment with any suitable solvent.

The shoe tree shown in Fig. 8 may then be completed by securing an assembled bridge 84 and a celluloid covered spring heel piece 86 (only part of which isshown in Fig. 8)

to the toe piece of the form by riveting the bridge to the tabs 14 by rivets 88. If desired, the outwardly extending arms of the bridge 84 may be provided with slots for the reception of the rivets 88so that the natural resilience of the toe piece will be more effective to press it into engagement with the in step of a shoe to which it is applied.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is 1. The method of making a hollow shoe form of sheet material, which consists in chemically tempering a blank of sheet material'capable of being molded while in temper and of'shrinking and setting as the tempering agent evaporates, wrapping said tempered blank around a model, applying resilient pressure to the blank to force it against the top and sides of the model and to overlap marginal portions of the blank on the bottom of the model, and clamping said overlapped marginal portions of the blank against the model, said'pressure and said clamping being continued until the blank shrinks and sets.

'2. The method of forming hollow articles from sheet material, which consists in wrapping a sheet of tempered material, capable of being molded while in temper and of shrinking and stifiening as the tempering agent evaporates, about a suitably shaped model, resiliently banding the material to the model, and'holding the material so banded while it shrinks and 'stifl'ens.

3.- The methodof making hollow articles from sheet material, which consists in wrapping about a model a tempered sheet of material capable of being-molded while in temper and becoming stiif upon evaporation of the tempering agent, reslliently'banding said sheet to the model and continuing the band ing pressure until the sheet becomesstifi but has not completely set, unbanding the sheet, and holding the sheet on-the model while it shrinks'it to tight engagement therewith.

'4. The method of making ahollow shoe form of sheet material, which consists in wrapping around a model'a previously tempered blank capable of being molded while in temper and of shrinking and stiffening as the tempering agent evaporates, one margm of said blank being positioned. closely adjacent to the margin of the bottom of the model, resiliently banding said margin of the band, applying tension lengthwise of-the model, and sliding the banded margin of the blank toward the'bottom of the model thereby to draw the margin of the; blank around the corner of the model to form an inturned flange overlying a portion of the bottom of the model.

5. The method of making a hollow shoe form of sheet material, which consists in wrapping a blank of tempered material around an end portion of a model, securing opposite marginal portions of the blank to he bottom of the model, thereby forming inturned bottom flange portions adjacent to the sides of the model, molding marginal portions of the blank over the bottom oi said end portion of the model by applying resiliently exerted pressure to form an in turned bottom flange portion around the end of the model, and clamping the inturned bottom flange portions tightly against the bot tom of the model.

6. The method of making a hollow shoe form of sheet material which consists in wrapping a tempered blank around a model, resiliently banding a margin of the blank and model to draw that portion of the blank which will make the instep of the form tightly against the model, and pressing another marginal portion of the blank against the model and clamping it there temporarily.

7. The method of making a hollow shoe form of sheet material, which consists in causing marginal portions of a previously tempered blank to overlapthe bottom of a model temporarily securing said margins to the bottom of the model, resiliently banding a portion of the form to press it against the model, and clamping the overlapping marginal portions of the form against the bottom of the model by pressure superposed on the banding pressure. r

8. The method of making a hollow shoe form of sheet material, which consists in wrapping around a model a tempered blank capable of being molded while in temper and of shrinking and stiflening as the tempering agent evaporates, resiliently banding a portion of the blank and model to press the blank into close contact with the model, clamping marginal portions of the blank flat ly against the bottom of the model by pres sure superposed temporarily on the banding pressure, allowing the blank to stiffen, relieving the banding pressure without removing the clamping pressure, allowing the blank to become completely dried and shrunk to the model, and later unclamping the blank and removing the hollow shoe form from the model.

9. The method of making a hollow shoe form of sheet material, which consists in wrapping around a model a previously tempered blank capable of being molded while in temper and of shrinking and stiffening as the tempering agent evaporates, clamping the margins of said blank to the bottom of the model, resiliently banding a portion of the blank and model to press the blank tightly'against the'corresponding portion of the model and holding the blank so positioneduntil it stiiiens, relieving the banding pressure from the blank, and maintaining the blank in clamped relation to the model while it shrinks into tight engagement therewith. 10. The method of making a hollow shoe form of sheet material, which consists in wrapping around a model a blank or" sheet celluloid tempered by the use of a temperingagent including a solvent, securing the inturned margins of the blank to the bottom of the model, resiliently banding the blank and model to apply pressure lengthwise of the model to cause the blank to conform to the'end portion thereof, sliding a banded margin of the blank to cause it to overlap the bottom or the model to form an inturned flange around the end portion of the bottom of the model, clamping said inturned flange to the bottomof the model, resiliently banding another separated portion of the blank to force it against. the model, continuing the pressure applied until the blank starts to set,

then relieving said banding pressure and leaving the blank clamped on the model until it has shrunk into tight engagement therewith.

11. An apparatus for use in producing hollow shoe forms comprising a last-like model over the toe portion of whicha resilient band may be stretched to assist in bringing a blank into close engagement with the model, said model being provided with a projecting hook in the bottomot the model positioned beyond the surface covered by the blank to receive and securely hold one end of the resilient band when. it is tensioned over the toe end otthe blank and model, the bent end of said hook being directed away from the toe end of the model. v 1

12. An apparatus for use in molding hollow articles of sheet material comprising a model, said model being provided with a plurality of studs on its bottom portion to which marginal portions of a blank of sheet material may be secured, a clamping plate adapted to overlie the bottom of the model constructed and arranged to press the said marginal portions of the blank into close engagement therewith, and means for detachably securing said plate in clamping position.

' 13. An apparatus for use in molding hollow articles or" sheet material comprising a model, said model being provided with a plurality of studs on its bottom portion to which marginal portions of a blank of sheet material maybe secured, a clamping plate apertured to receive said studs and constructed and arranged to press the said marginal portions of the blank into close engagement with the bottom of the model, and means for detachably securing said plate in clamping position.

14. An apparatus for use in forming hollow articles of sheet material comprising a model, a clamping plate constructed and arranged to overlie the bottom of the model 7 and the marginal portions of a blank to press the latter into close engagement with the model, and means for detachably securing said plate in clamping position.

15. An apparatus for use in forming hollow articles-of sheet material comprisinga model, a resilient band pressing a portion of a blank against the model, a clamping plate constructed and arrangedto overlie a portion of the band and of the blank to force the blank into contact with the model by pressure applied through said band, and means for detachably securing said plate in clamping position. I

16. An apparatustor use in making hol low shoe forms comprising a model shaped like the forepart of a shoe-last, said model being provided with a retaining hook andwith a plurality of studs adapted for interlocking engagement with a blank on the model, a resilient band wrapped around the toe portion of the blank and the model and 7 said hook, a clamping plate overlying por-" tions of said band and of said blank to press the latter against the bottom face of the model, and means for detachably securing said plate in clamping position.

17. An apparatus for use in molding hollow shoe forms from sheet material comprising a last-shaped model, said model being-provided with a gage memberadjacent to its instep portion to-assist the user in locating the rear edge ofthe blank upon the model. V

In testimony whereof we have signed our names to this specification. SEXTUS- A. EDDINS.

GERALD M. HANNIGAN.

CERTIFICATE OF CORRECTION.

Patent No. 1,880,920. October 4, 1932.

SEXTUS A. EDDINS ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 4, line 117, claim 3, for the words "it to" read into; and line 127, claim 4, for "band" read blank; page 5, line 32, claim 7, after "model" insert a comma; and that the said Letters Patent should be read with these corrections therein that the .same may conform to the record of the case in the Patent Office. I

Signed and sealed this 29th day of November A. I). 1932.

M. J. Moore,

(Seal) Acting Commissioner of Patents. 

